// Copyright 2025 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package cloudsqlcloneinstance

import (
	"context"
	"fmt"

	yaml "github.com/goccy/go-yaml"
	"github.com/googleapis/genai-toolbox/internal/sources"
	"github.com/googleapis/genai-toolbox/internal/sources/cloudsqladmin"
	"github.com/googleapis/genai-toolbox/internal/tools"
	"github.com/googleapis/genai-toolbox/internal/util/parameters"
	sqladmin "google.golang.org/api/sqladmin/v1"
)

const kind string = "cloud-sql-clone-instance"

func init() {
	if !tools.Register(kind, newConfig) {
		panic(fmt.Sprintf("tool kind %q already registered", kind))
	}
}

func newConfig(ctx context.Context, name string, decoder *yaml.Decoder) (tools.ToolConfig, error) {
	actual := Config{Name: name}
	if err := decoder.DecodeContext(ctx, &actual); err != nil {
		return nil, err
	}
	return actual, nil
}

// Config defines the configuration for the clone-instance tool.
type Config struct {
	Name         string   `yaml:"name" validate:"required"`
	Kind         string   `yaml:"kind" validate:"required"`
	Description  string   `yaml:"description"`
	Source       string   `yaml:"source" validate:"required"`
	AuthRequired []string `yaml:"authRequired"`
}

// validate interface
var _ tools.ToolConfig = Config{}

// ToolConfigKind returns the kind of the tool.
func (cfg Config) ToolConfigKind() string {
	return kind
}

// Initialize initializes the tool from the configuration.
func (cfg Config) Initialize(srcs map[string]sources.Source) (tools.Tool, error) {
	rawS, ok := srcs[cfg.Source]
	if !ok {
		return nil, fmt.Errorf("no source named %q configured", cfg.Source)
	}
	s, ok := rawS.(*cloudsqladmin.Source)
	if !ok {
		return nil, fmt.Errorf("invalid source for %q tool: source kind must be `cloud-sql-admin`", kind)
	}

	project := s.DefaultProject
	var projectParam parameters.Parameter
	if project != "" {
		projectParam = parameters.NewStringParameterWithDefault("project", project, "The GCP project ID. This is pre-configured; do not ask for it unless the user explicitly provides a different one.")
	} else {
		projectParam = parameters.NewStringParameter("project", "The project ID")
	}

	allParameters := parameters.Parameters{
		projectParam,
		parameters.NewStringParameter("sourceInstanceName", "The name of the instance to be cloned."),
		parameters.NewStringParameter("destinationInstanceName", "The name of the new instance that will be created by cloning the source instance."),
		// point in time, preferred zone and preferred secondary zone are optional
		parameters.NewStringParameterWithRequired("pointInTime", "The timestamp in RFC 3339 format to which the source instance should be cloned.", false),
		parameters.NewStringParameterWithRequired("preferredZone", "The preferred zone for the new instance.", false),
		parameters.NewStringParameterWithRequired("preferredSecondaryZone", "The preferred secondary zone for the new instance.", false),
	}
	paramManifest := allParameters.Manifest()

	description := cfg.Description
	if description == "" {
		description = "Clone an existing Cloud SQL instance into a new instance. The clone can be a direct copy of the source instance, or a point-in-time-recovery (PITR) clone from a specific timestamp. The call returns a Cloud SQL Operation object. Call wait_for_operation tool after this, make sure to use multiplier as 4 to poll the opertation status till it is marked DONE."
	}

	mcpManifest := tools.GetMcpManifest(cfg.Name, description, cfg.AuthRequired, allParameters, nil)

	return Tool{
		Config:      cfg,
		Source:      s,
		AllParams:   allParameters,
		manifest:    tools.Manifest{Description: description, Parameters: paramManifest, AuthRequired: cfg.AuthRequired},
		mcpManifest: mcpManifest,
	}, nil
}

// Tool represents the clone-instance tool.
type Tool struct {
	Config
	Source      *cloudsqladmin.Source
	AllParams   parameters.Parameters `yaml:"allParams"`
	manifest    tools.Manifest
	mcpManifest tools.McpManifest
}

func (t Tool) ToConfig() tools.ToolConfig {
	return t.Config
}

// Invoke executes the tool's logic.
func (t Tool) Invoke(ctx context.Context, resourceMgr tools.SourceProvider, params parameters.ParamValues, accessToken tools.AccessToken) (any, error) {
	paramsMap := params.AsMap()

	project, ok := paramsMap["project"].(string)
	if !ok {
		return nil, fmt.Errorf("error casting 'project' parameter: %v", paramsMap["project"])
	}
	sourceInstanceName, ok := paramsMap["sourceInstanceName"].(string)
	if !ok {
		return nil, fmt.Errorf("error casting 'sourceInstanceName' parameter: %v", paramsMap["sourceInstanceName"])
	}
	destinationInstanceName, ok := paramsMap["destinationInstanceName"].(string)
	if !ok {
		return nil, fmt.Errorf("error casting 'destinationInstanceName' parameter: %v", paramsMap["destinationInstanceName"])
	}

	cloneContext := &sqladmin.CloneContext{
		DestinationInstanceName: destinationInstanceName,
	}

	pointInTime, ok := paramsMap["pointInTime"].(string)
	if ok {
		cloneContext.PointInTime = pointInTime
	}
	preferredZone, ok := paramsMap["preferredZone"].(string)
	if ok {
		cloneContext.PreferredZone = preferredZone
	}
	preferredSecondaryZone, ok := paramsMap["preferredSecondaryZone"].(string)
	if ok {
		cloneContext.PreferredSecondaryZone = preferredSecondaryZone
	}

	rb := &sqladmin.InstancesCloneRequest{
		CloneContext: cloneContext,
	}

	service, err := t.Source.GetService(ctx, string(accessToken))
	if err != nil {
		return nil, err
	}

	resp, err := service.Instances.Clone(project, sourceInstanceName, rb).Do()
	if err != nil {
		return nil, fmt.Errorf("error cloning instance: %w", err)
	}

	return resp, nil
}

// ParseParams parses the parameters for the tool.
func (t Tool) ParseParams(data map[string]any, claims map[string]map[string]any) (parameters.ParamValues, error) {
	return parameters.ParseParams(t.AllParams, data, claims)
}

// Manifest returns the tool's manifest.
func (t Tool) Manifest() tools.Manifest {
	return t.manifest
}

// McpManifest returns the tool's MCP manifest.
func (t Tool) McpManifest() tools.McpManifest {
	return t.mcpManifest
}

// Authorized checks if the tool is authorized.
func (t Tool) Authorized(verifiedAuthServices []string) bool {
	return true
}

func (t Tool) RequiresClientAuthorization(resourceMgr tools.SourceProvider) bool {
	return t.Source.UseClientAuthorization()
}

func (t Tool) GetAuthTokenHeaderName() string {
	return "Authorization"
}
